Such tail stocks as commonly provided include a ram structure having a tapered socket for accomodating a center drill, a tap, a thread cutter, a reamer or the like. The ram is movable longitudinally along an axis corresponding to the axis of rotation of the engine headstock. Such devices are usually provided with a lead screw machanism for advancing and retracting the ram. Such prior art devices comprise a handwheel and lead screw ram feed which operates at a slow rate and does not provide for a fast in-and-out motion, greater leverage and a better feel of how the tool is cutting. Other prior art tail stock mechanisms have provided for advancing and retracting of the ram by use of a rack and pinion mechanism. In order for such tail stock ram drive mechanisms to be successful and practical, it must be adaptable to different sizes and styles of tail stocks without major modifications, it must provide for faster advancing and retracting of the ram, better feel of how the tool is cutting, improved work center capabilities and it must be economical to manufacture and install without adding greatly to the cost of the tail stock ram drive or altering the otherwise conventional parts. Prior art devices of this general character have failed to measure up fully to the above requirements and as yet no completely satisfactory tail stock ram drive mechanism has been devised.
It is therefore a desired object of this invention to provide a tail stock ram drive mechanism that meets all the above needs and requirements.